Backup of data is probably the most neglected aspect of
system administration in small businesses and home offices. Yet it
can be critical. If your entire business is riding on the contents
of your hard drive, and it goes belly-up, you are out of business.
Worse, you may be legally liable. For example, you may be required
to meet your payroll within a certain time after the end of the pay
period.

For these reasons, what you spend on backup, including
software and tapes, is a form of insurance. To give one example, I
administer a home office with five computers (two Linux, two
Windows 95, and one that multiboots between Linux, Windows NT and
Windows 95), and two users. The network is standard 10-base T. I
have two tape drives (a Conner/Seagate 4GB Travan and an HP DDS 3
DAT drive) and routinely use two of the products I discuss
here.

Four backup programs for Linux are reviewed below:
PerfectBACKUP+, Arkeia, BRU, and Quick Restore. The first three are
available on the Web. Arkeia comes packaged with Red Hat, Mandrake
and SuSE distributions of Linux. Quick Restore is available on CD
only.

PerfectBACKUP+

This is the only completely “no charge” program in the lot,
and coming into such a program, I was not expecting much. I was
surprised, for example, to see support for tape changers, something
I would not expect to see on a low-end backup program. However, the
program qualifies as “nagware” by giving you a “please
register” window when you start up the program (see Figure
1).

Figure 1. The Main Window of
PerfectBACKUP+

I was very pleased to see that it detected and correctly
identified both of my SCSI tape drives. Whether this facility
extends to other interfaces I cannot say. The two drives were not
associated with the correct device files in /dev, so I hand edited
that. A quibble indeed, compared to the setup problems I have had
with other tape backup software.

One thing that is very nice about PerfectBACKUP+ is that the
device selection menu identifies the drives by their names as
provided by the device. That is very useful; it saves having to
remember device names.

Figure 2. Selecting a Destination Drive for a
PerfectBACKUP+

PerfectBACKUP+ provides some easy-to-use minimal acceptance
tests, a facility I'd like to see on other backup software. One
quibble here is that I'd like to see the software test with larger
data sets to better exercise the tape drive. The data set is
unfortunately so small as to make the data rate result
meaningless.

Defining a backup set (or package, in PB's terminology) is
easy: go down the Backup pull-down menu and define each
characteristic in turn. Then select the Save As Package menu entry,
and give it a name. You can then recall the package and run it all
you want. I was able to define a small test backup set and make the
backup easily.

Unfortunately, the restoration had problems. I got a cryptic
message about “This backup was made from / and you are about to
restore it to /test. If your backup was RELATIVE you might not want
to do this.” Relative to what? Grepping the documentation, I found
no explanation of what the term “relative” means. It then asked
if I wanted to change the working directory. If I refused, it gave
me a cryptic error message. If I accepted, and retyped the working
directory I had previously selected, it made the restore where I
had asked for it.

This is the kind of glitch that indicates inadequate testing.
I can accept that sort of glitch in the GUI, as long as I can work
around it. But I am left with the question: what else was not
adequately tested? Also, PerfectBACKUP+ left defunct processes on
my test computer. This is not encouraging.

Verification is easy. In addition, after the fact—weeks or
months—you can pop a tape into a drive and verify it. You can
verify the contents of the tape against the original files, or you
can run a CRC checksum verification against the tape alone. This is
useful for verifying the reliability of your tape drive: remounting
a tape is a good test of the repeatability of head positioning, a
major casualty of wear in lower-end tape drives like QIC
tapes.

Unfortunately, I saw no way to verify a backup as part of the
backup sequence. This is something I have been accustomed to seeing
in PC backup software since Colorado Memory System's software
provided it in the late 1980s.

There are two sets of documentation. One is in HTML, and you
read it via Netscape. (What happens if you don't have Netscape?)
The documentation screen shots indicate an xterm interface with
mouse support; however, the provided interface is a full X GUI. The
other documentation is available from pull-down menus on the GUI.
It has no search function, and uses a fixed font which is
vanishingly small if you have a high-resolution monitor. The two
sets of documentation contain different material. Neither one
documents the command-line interface, which is a pity.

I must reluctantly conclude that PerfectBACKUP+ is not yet
ready for prime time. It needs serious testing in the GUI and a lot
of cleanup in the documentation. Because it left defunct processes
on my system during my tests, I don't trust it. PerfectBACKUP+ has
some excellent features, like identifying drives by name. I hope
Merlin fixes its problems and makes a more solid version
available.